Objectives: To assess the long-term (4-year) follow-up of urethral submucosal collagen injection for the treatment of stress urinary incontinence (SUI). Submucosal collagen injections are an acceptable alternative to surgery in the treatment of selected cases of SUI. Most published studies report 1 to 2-year results, with long-term data still being questioned despite the low morbidity and cost-effectiveness of this relatively recent technique.
Methods: Forty women with genuine SUI confirmed by clinical and urodynamic evaluation were treated with periurethral collagen injection. Clinical and urodynamic follow-up lasted an average of 50 months (range 47 to 55).
Results: Totally favorable results, including improvement (40%) and cure (30%), were recorded in 28 patients. Other than three lower urinary tract infections, no complication was noted. For the entire group of patients, the average number of injections in the first 6 months was 2.2, with an average volume of 9.0 mL of collagen injected. The reinjection rate ("top up injection" after completion of treatment) was 33% in an average of 20 months, and the average amount of collagen used for this purpose was 5 mL.
Conclusions: The safety, low morbidity, and long-term outcome of periurethral collagen injection for genuine SUI are encouraging. Multivariable analysis involving a larger number of patients is necessary to determine the predictive factors of success or failure to better define the indications for this noninvasive procedure.